AES Tietê reported strong operational and financial results in 2Q10. Energy generation was 33% higher than the physical guarantee and EBITDA was R$299 million with a 74% margin. Net income was R$172 million and the company distributed 100% of the result to shareholders. The company also issued R$900 million in debentures to pre-pay debt, reducing costs. Reservoir levels remained high and investments focused on maintenance and new hydroelectric projects.

1. 2Q10 Results
August, 2010

2. Operational
Operational  Energy Generation 33% higher than physical guarantee in 2Q10
 Ebitda reached R$ 299 million, with margin of 74%, in 2Q10
Financial
Financial
 Provision in the amount of R$ 9 million related to administrative lawsuit regarding
federal tax compensation
 Net income of R$ 172 million in 2Q10
 1st debenture issuance in the amount of R$ 900 million and pre-payment of the only
outstanding debt on May 4, 2010. Exchange of debt brought savings of approximately R$
14 million in the quarter.
 Dividend distribution in the amount of R$ 172 million related to 2Q10, representing R$
Dividends
Dividends
0.43 for ordinary shares and R$ 0.47 for preferred shares.
Subsequent
Subsequent  Annual readjustment of bilateral contract with AES Eletropaulo by IGP-M at 5.17%; the
Event
Event energy price increased from R$ 152.00/MWh to R$ 159.85/MWh
 The Board decided to: (i) not file an autonomous claim against Aneel; and, (ii) summon
an Extraordinary General Meeting to deliberate on the matter
2

3.  AES Tietê reservoirs levels closed at 89% and the stored energy in the southeast region
was kept well above the Risk Aversion Curve in 2Q10
Reservoirs Level- (%) Risk Aversion Curve – Southeast Submarket
80
% of Maximum Stored Energy
97.2
60
90.2
94.3
94.2
91.0
73.3
79.0
40
70.0
65.5
72.6
54.5
40.9
20
-
Southeast South Northeast North Jan Apr Jul Out
2Q10 2009 2010 CAR
2009 2Q09
Source: National Electric System Operator – ONS 3

4.  Maintaining high operational availability. Generated energy 38% higher than
physical guarantee in 1H10
Energy Generation – MW Avg.1
138%
130%
121%
119%
115% 1,809
112%
1,665
1,545 1,512
1,467 1,425
2005 2006 2007 2008 2009 1H10
Generation – MW Avg. Generation / Physical Guarantee
1- Generated energy divided by the amount of period hours 4

5.  Billed energy was 5% higher due to greater volume of secondary energy in 2Q10
Billed Energy – GWh
Spot Market 7,880
10 %
7,135 949
MRE1
463 5%
1,146
1,146 132 3,605
Other Bilateral Contracts 1,105 3,438
33
239 306
5,653 433 19 580
AES Eletropaulo 5,534 80
2,639
2,747
1H09 1H10 2Q09 2Q10
5
1 – Energy Reallocation Mechanism

6.  Investments of R$ 16 million in maintenance and modernization of power plants and
R$ 1 million in Jaguari Mirim SHPPs1 in 2Q10
Investments – R$ million Investments 2Q10
New SHPPs
1%1%
Investments
67 7%
59 57 9
20 13
91%
58 16
44 9
39 1
4 15
5
Equip. and Maint. New SHPPs
2008 2009 2010(e) 2Q09 2Q10
IT Environment
6
1 – Small Hydro Power Plants

7.  Opportunities to increase installed capacity:
Concluded
Concluded  6 MW of co-generation through biomass, contracted for 15 years from 2010
(PPA1)
(PPA1)
Under
Under  7 MW of hydro generation through SHPPs2 in Jaguari Mirim River
Construction
Construction – São José SHPP (4 MW) has an estimated start-up in 1H11
– São Joaquim SHPP (3 MW) has an estimated start-up in 1H11
Under  550 MW of thermo generation through natural gas
Under
Development
Development – Location has been defined in Nov/2009
– Environmental licensing process initiated in March 2010
– Technical feasibility study in advanced stage
 22 MW of hydro generation through one SHPP, in stage of technical and economic
feasibility studies
7
1 – Power Purchase Agreement 2 – Small Hydro Power Plants

8.  Bilateral Contract with AES Eletropaulo
2000 - 2003 2005 - 2007 2010
 2000  2005  August, 2010
– Aneel1 approved the bilateral – Aneel denied approval to the – The administration of AES
contract signed by the Company amendment Eletropaulo has chosen to
and AES Eletropaulo valid until – AES Eletropaulo placed a request withdraw the lawsuit
the end of 2015 for an administrative remedy – The administration of AES Tietê
appeal at Aneel and filed a decided not to file an
lawsuit against Aneel autonomous claim against Aneel
regarding the extension of the
 2003  2007 contract due to the remote
– Aneel dismissed AES chance of obtaining a final
— AES Tietê and AES Eletropaulo
Eletropaulo’s administrative decision before 2015; and (ii)
signed an amendment to the
remedy appeal and upheld its summon an Extraordinary
bilateral contract, submitted to
decision of denying the General Meeting to deliberate on
Aneel for approval, which
amendment the matter
extended its duration to June
14, 2028
8
1 – Brazilian Electric Energy Agency (Regulator)

9.  Allocation to 1Q10 of part of annual volume to be sold to AES Eletropaulo contributed
for 3% reduction in net revenues
Net revenues – R$ million
862
832 26
4% 17
36
5
3%
414 403
791 819 20 10
2 10
392 383
1H09 1H10 2Q09 2Q10
AES Eletropaulo Other Bilateral Contracts CCEE / MRE
9

10.  Costs were impacted by provision related to administrative lawsuit regarding federal
tax compensation, increase on energy purchased for resale and spending on
equipment and third parties
Costs and operational expenses1 – R$ million
186
165
16
57 10% 67 12% 103
90
11
Operational Provisions
30
Other Costs and Expenses2 108 103 37
60 55
Energy Purchase, Transmission
and Connection Charges,
and Water Resources
1H09 1H10 2Q09 2Q10
1 – Do not include depreciation and amortization 2 - Personnel, Material, Third Party Services and Other Costs and Expenses 10

11.  8% reduction on Ebitda, with 74% margin
Ebitda – R$ million
80% 78% 78%
74%
2% 8%
Ebitda Margin 677
667
325
299
1H09 1H10 2Q09 2Q10
11

12.  Negative impact due to 1,24 b.p. increase in IGP-M from April to May, 4th 2010.
Disregarding debt exchange, the financial result would be reduced in R$ 14 million
Financial Result – R$ million
1H09 1H10 2Q09 2Q10
(4)
(7)
378% 217%
(21)
(22)
12

13.  Company registered a net income of R$ 172 million in 2Q10 and will distribute 100% of
the result
Net Income – R$ million
100% 100% 100% 100%
1%
414
Pay-out
411 13%
199
172
1H09 1H10 2Q09 2Q10
13

14.  Cost of debt was reduced from IGP-M + 10% p.a. to CDI + 1,20% p.a.
Net Debt 2Q10 Characteristic of 1st debenture issuance
 R$ 900 million
0.3x 0.3x 0.3x 0.4x
 Period of 5 years
 CDI + 1,20% p.a.
 Biannual basis interest payment
0.4 0.4 0.4 0.4  Annual amortization and equal installments in the
3rd, 4th and 5th years
 Purpose: Pre-payment of Eletrobrás Debt
2008 2009 2Q09 2Q10
Net Debt Net Debt/ Ebitda
14

15.  Growth of 4% in operational cash flow generation
Consolidated Managerial Cash Flow – R$ million
2Q09 1Q10 2Q10
Initial Cash 814 615 574
Operational Cash Generation 332 368 346
Investments (9) (8) (16)
Net Financial Expenses (13) (12) (4)
Net Amortization (55) (60) (34)
Income Tax (20) (328) (33)
Free Cash Flow 236 (41) (259)
Dividends and Interest on Equity (409) 0 (379)
Final Cash 641 574 455
15

16.  40% growth in daily average volume traded in 2Q10
AES Tietê X Ibovespa X IEE Daily Avg. Volume - R$ thousand
-
12 months 14,231
140 10,187
130
+ 18%
8,160
120
+ 18% 9,583
110 8,086
100 + 2% 5,468
90
80 GETI4
IEE
Jun-091 Sep-09 Dec-09 Mar-09 Jun-10
4,648
2,692 2,101
IBOV
110 2Q10
105 + 8% 2008 2009 2Q10
100
- 1%
95 Preferred Common
90
-13%
85
80
Mar-102 Apr-10 May -10 Jun-10
16
1 – Index: 06/30/09= 100 2 - Index: 03/31/10 =100

17. 2Q10 Results
The statements contained in this document with regard
to the business prospects, projected operating and
financial results, and growth potential are merely
forecasts based on the expectations of the Company’s
Management in relation to its future performance.
Such estimates are highly dependent on market
behavior and on the conditions affecting Brazil’s
macroeconomic performance as well as the electric
sector and international market, and they are therefore
subject to changes.
.